That first one gives us a clue. They are only guessing at the actual percentages. Minimum and Maximum are given. This is not a precisely controlled process.

The second one, the one we are really talking about, gives various percentages that add up to more than 100%. That should strike you as a bit odd. However, each ingredient has another indication, either "min" or "max". "min" means there is AT LEAST the given percentage in the mix. "max" means there is AT MOST the given percentage in the mix. It's not perfectly clear to me how to adjust for this except to say that if the manufacturer doesn't know how much of each ingredient is in the mix, how can you expect to calculate it?! If it were me, I would just scale it. Do whatever correct thing you already did - the one that came to around 53 - and divide everything by 1.0575. That should get you close.

The third is as I predicted - multiple types of measurements. PPM is okay, since that's just like a percentage. 1% = 1 PPH or 1 Part per hundred. 1 PPM is just 1 part per Million and would be difficult or relatively useless to report as a percentage compared to such large values as 1.5%. It may be difficult to imagine that 1.5% is the LARGE number in this scenario.

85 PPM = 85 parts per 1,000,000

8.5 parts per 100,000

0.85 parts per 10,000

0.085 parts per 1,000

0.0085 parts per 100 = 0.0085% - It's a pretty small piece.

I'm afraid that's the good news. IU/lb doesn't have that kind of conversion.